Safety device for moving picture projectors



NOV. 26, 1940. J JACQBSON ETAL 2,222,666

SAFETY DEVICE FOR MOVING PICTURE PROJECTORS Filed March 22, 1959 2 Sheets-Sheet 1 "TNvENToRs Jbsep/z Jacobsou, 5 Nathan Gfaruzisdeuz 1940- J. JACOBSON ET AL 2,222,655

SAFETY DEVICE FOR MOVING PICTURE PROJECTORS Filed March 22, 1939 2 Sheets-Sheet 2 INVENTORS Jose h JaCObSoza Nathan Granatis'zfeaw BY f I Patented Nov. 26, 1940 2,222,666

SAFETY DEVICE FOR MOVING PICTURE PROJECTORS Joseph Jacobson and Nathan Granatstein,

, Brooklyn, N. Y.

Application March 22, 1939, Serial No. 263,322

4 Claims. (01. 177-311) The present invention relates to a safety deand take-up reels, which will be connected to a vice for motion picture projectors and it parsuitable electrical circuit to close or open said ticularly relates to a safety device which may be circuit as the case may be and to cut off the actuated upon breakage or jamming of th film beam of light and/or cause stoppage of the ma- 5 and thus reduce the possibility of fire in and chine and projector where the film has blocked around the projection apparatus in case of a or jammed up or becomes loose and there is mishap to the film. possibility of ignition thereof.

In the usual type of motion picture projector In one form of the device, a roller is caused to the film is carried from a feed reel to a take-up contact with the film and is provided with a rod reel across a very powerful beam of light having connected to a linkage actuating a sliding m a very high he ti fi ct switch. This switch has a contact member If the film intercepts such beam of light and which rides over two arcuate contact elements does not move rapidly through the beam, the when the film is in normal actuating position, film would be heated up sufiiciently in relatively closing a circuit, which in turn energizes and short time to the ignition point and would closes a relay switch. 15 readily take fire. When the contact member moves off the con- Most moving picture apparatus are therefore tact elements, the circuit will be opened, the redesigned to cause movement of the film across l y w ch will be opened and a shutter will be the beam of light at such a rate and with such operated to cut oil the beam of light.

blocking devices as may cut off the light momen- Desirably the r0 is 80 ra d as 170 con- :0 tarily as each frame passes, so that there will be ct W t t e fi a i a p ed t ou insufiicient opportunity for the film to heat up the beam of light and just before it is about to with resultant tendency toward ignition. pass through the sound head or onto the roller However, in case there is any breakage in the p reel, as i has en found the most 26 film or other mishap in the apparatus which satisfactory position for precautions against causes the feed and movement of the film across jammings or breakages in the film. the power of the beam of light, the film may t has also been und ime satisfactor to block up or jam up in such a way that a portion arrange a au y Signal circuit, which ay of it will be exposed or be held in the beam f actuate either a buzzer or light or both to indi- 30 light a sufiicient length of time to cause ignition, cate when the contactor is about to pass oil the 30 and it is among the objects of the present incontacts and op the Circuit d fo this latvention to provide a safety device which will so el p p s auxiliary /ac or or switch may cooperate with the film and control the passa be provided with two additional contact elethereof as to shut on the projector and also the m s- T e circuit across i i ry switch light in such a short time as to eliminate th is closed just before the circuit controlling the 35 possibility of fire. machine relay is opened, so that there will be 9.

Another object of the present invention is to Preliminary buzzing 0! light in c o Signalprovide a signal system for a moving picture l g t e Op a r t t there is danger and that projector which will first give warning of any the film is no fu c ioning in the proper manmishap to the film in passing through the pr ner in passing from the feed reel to the take-up w jecting apparatus and will then shut ofi the proreel. jector altogether if there is any tendency of when the $8118.! has bee given in the preignition. ferred form of invention and when ,the circuit Still further objects and advantages will apis broken, to assure that the beam of light will pear from the more detailed description set forth be immediately cut off, it has been found most below, it being understood, however, that, this satisfactory to use a solenoid control which will more detailed description is given by way of ilimmediately place a shutter across the beam of lustration, since various changes therein may be light and prevent further heating of the film and made by those skilled in the art without depai'tpossible ignition thereof.

ing from the scope and spirit of the invention. At the same time, if desired, the relay con- 9 In accomplishing the above objects, it has trol may also be actuated to cause a cut off for been found most satisfactory according to one the motor of the machine and a stoppage of the embodiment of the present invention to provide feed of current to the are light or other source a follower member which may cooperate with or of illumination.

contact the film in its passage between the feed Referring to the drawings which illustrate sevll vention is by no means restricted, since the drawings are merely by way of illustration and not by way of limitation,

Fig. 1 is a diagrammatic side view illustrating the feed of the film across the beam of light and the positioning of the protector device of the present application in respect to such film and the feeding mechanism therefor,

Fig. 2 is a diagrammatic fragmentary transverse sectional view upon the line 2-2 of Fig. 1 showing the light cut oil device,

Fig. 3 is a perspective view of the safetyv apparatus inverted and turned around from the position as shown in Fig. 1,

Figs. 4 to 6 are sectional views of the safety device control, Fig. 4 being a transverse sectional view upon the line 4-4 of Fig. 3, Fig. 5 being a transverse sectional view upon the line H of Fig. 4, and Fig. 6 being a transverse sectional view upon the line 6-8 of Fig. 4, and Fig. 'I is a wiring diagram illustrating the electrical connections between the various elements of Figs. 3 to 5.

Referring particularly to Fig. 1, the compartment In is usually provided with a high powered are light which projects a beam of light, indicated diagrammatically by the long arrow II.

The film I9 is fed from the feed reel I2 across the upper sprocket it through the holder members I 4 and II, which hold the film in the path of the beam of light II, the lower feed roller II and I! through the sound equipment indicated diagrammatically at onto the take-up reel It.

It will be noted that the film is provided with suitable slack at 20-20.

The safety control device of the present application is indicated at A in Fig. 1 and is pro- .vided with a box 2| having the rod 22 and the follower roller 23 which contacts the film in the position 24.

The light beam cut of! may be of the type shown in Fig. 2. In Fig. 2 the window IIII in the plate III may be cut oil by the screen or plate 2 when said plate is lowered, as indicated by the arrow I II.

The plate 2 may have suitable guides, not shown, to guide its reciprocatory movement. The upper ear extension III of the plate H2 is pivotally connected to the end of the long arm ll! of the bell crank lever I II. The bell crank lever is pivotally mounted at I" and its short arm is connected at ill to the bar member H9, which is actuated by the solenoid I26.

Upon energization of the solenoid, the bell crank lever III will be actuated so as to throw the cut of! H2 downwardly and close 01! the window Ill! and prevent the beam of light actuating upon the film.

As best shown in Figs. 3 to 6, where the control device A is shown in inverted position as compared to Fig. 1, the box 2| may be provided with an enclosure member 26 and a lid 26 having the side flanges 2! with the screws "holding said side flanges in position.

The rod 22 is provided with the bearing members 26 and III which are held against the side walls II and 22 by the flanges SI and 34 (see Fig. 4).

The roller. or contact element 22 is provided with a depressed portion II which receives the film, the film being held in position between the elevated ridges.

The roller 28 fits upon the rod 31, the ends of which carry the nuts ll. The nuts II hold the rod II upon .the side flanges I! of the U- member 40. -The base of the U-member II is bolted upon the transverse portion ll of the T member 42 by the short bolts 43 extending 6 through the slots a.

The stem of the T is tubular and receives the end 44 of the rod 22, said stem 42 being held in position by the set screw 4'.

A spring 46 encircles the rod 22 between the bearing III and the T member 42 and tends to bias the rod outwardly in the direction indicated by the arrow 41 (see Fig. 4).

The rod 22 carries the collars 46 held in position by the set screws 46 between which is positioned the loosely mounted eye ll of the rod ll.

The rod II projects through the slot 62 (see Fig. 3) in the plate ll, held in position on the upper wall 54 of the box 26 by the rivets or screws 56. The upper end of the rods I has a handle 68.

It will be noted that the slot has a right angular end portion II into which the rod Il may be placed, when it is desired to lock the safety device A in inoperative position. When the safety device is in operative position. the rod II is in the straight portion of the slot as shown in Fig. 3.

The rod 22 also carries the collar I! held in position by the set screw- II. The collar 66 has the slotted extension ll in which fits the stud 62 (see also Fig. having the enlarged fillister head 63. The other end of the stud is fixed to the arm 64 which constitutes an extension of the contactor member ll. The contact member 66 is pivotally mounted at 66 upon the board 61.

The contactor member Cl is made of an insulating material such as Bakelite, hard rubber o some other material.

The contactor base 66 carries the contact elements 66 and 69, which, as shown, have end portions projecting upwardly through openings in the member 65, which are turned over and downwardly on the face of the contactor base 65, as shown in Fig. 4. The 'lower faces of these contactors 66 and 69 are designed to slide over the pairs of arcuate contact elements II and I I, which are attached to the insulating board 61. These contactor elements form part of the circuit which will be more fully described in connection with Fig. 7.

Referring to Fig. '7, the apparatus may be fed from a suitable D. 6., indicated diagrammatically at I2.

The main switch 85 positioned outside of the unit A is located on the negative line I4 and the 66 positive line 1!. The negative line II is connected to the negative side of the motor I6 by the connection 11, while the positive side of the line I6 is connected to the positive side of the motor I6 by the connections II and Ila passing through so the double throw switch 13. This switch I3 is shown as a snap switch at I! in Figs. 3 and 4.

The switch II in Fig. 7 will be either thrown against contactsm, n so as to cut in the automatic control of the present application, or 66 against contacts 0, p, in which case the automatic control will be cut out and a direct connection will be made between the lines I. and Ila.

The motor II will drive the feed sprockets ll, I6, I! and also control the rotational movement of the mounts for the slide and take-up reels l2 and I2 (seeFlg. 1).

As indicated in Fig. '7, with the automatic control operative, the motor circuit is constituted 16 as follows. The positive side of the line at 15 passes through the connection 18, the switch 18, the right contact m, the connections 85c and 82 through the relay arm 88, the contact 8| past the binding post 8Ia of Fig. 4, the binding post 8Ib of Fig. 4, the connection 88 to the left contact n, the line 18a, the motor 18, and the lines 11 and 14 to the switch 85.

The circuit of the solenoid I28 is constituted as follows. The negative side of the line 14 has a connection 84 to the solenoid I28, which also has the connection 85 to the binding post point 98 (see also Fig. 4), and then to the contact 89. The relay arm 88 is designed to cooperate with the contact 89 and in turn is connected with the binding post 81 and the connections 85 and 850, the contacts a, b, the switch element 59, the lines 85b and 850, the contact 1n, the connection 18 back to position 15 (see Figs. 4 and 7).

The circuit of the relay coil 91 includes the lines 85c, 85b, contacts 0, d, the switch element 68, the line 95, the binding posts 910. and 91b of Fig. 4, the lines 93 and 98a.

The circuit of the buzzer 94 extends from the contact 1n, the lines 85c, 851), the contacts a, b, the switch element 59, the line 85a, the switch 82, the lines I84, 99, 96a and 14.

The lamp I8I is placed in the circuit I82 and I83 (Fig. '1) across the motor circuit relay switch 83.

The negative line 14 it is noted is connected directly to the buzzer 94, the lamp IN, the motor 18, the solenoid I28 and the relay coil 91. All switches on the other hand, namely, switches 8I-83, 88-89, 13, 85-88-89, are connected to the positive.

The buzzer 94 (see Fig. 4) is provided with the coil I85, the yoke I88 and the buzzer element I81. The buzzer element I81 may be pivotally mounted, as indicated at I88 and swing back and forth between two coils I85 successively energized and deenergized.

The pilot light III may project through the wall 54 of the casing, as best shown in Figs. 3 and 4.

The main switch 18 may be positioned, as indicated in Figs. 3 and 4, and be readily available from the exterior of the casing 25. The buzzer switch 92 may be positioned as indicated in Figs. 3 and 4.

The main control relay R is provided with a coil 91 and the arms 83 and 88, which move in unison between contact and stop points with energization and deenergization of the solenoid 91.

In operation when the safety device of Figs. 3 to 6 is in operating position, as long as the bar 58 is in contact with the strips 0, d, a circuit will be established through the solenoid 91. The solenoid 91 when energized will elevate the relav arm 88 into contact with the contact point 8| and the contact arm 88 out of contact with the contact point 89. This will close the circuit of the motor 15 and open the circuit of the solenoid I 28.

As long as the switch 18 is closed to the contacts m, n. and the relay switch '88 is closed. the circuit of the lamp I 8| will be energized. The lamp I 8| will be lit only when the motor 18 is opening.

As soon, however, as the arm 85 has swung sufliciently far in the direction I38 to break the contact between the arcuate contacts 0 and d, the circuit will be opened, deenergizing the solenoid 91 and permitting the arms 83 and 88 to drop. This will open the circuit of the motor 18 and close the circuit of the solenoid I28.

As a result the shutter I I2 willbe thrown across the aperture II8 (Fig. 2), cutting off the beam of light I I.

The arcuate contacts a and b of the lower element 1| are associated with the buzzer 94 and when the contactor 89 passes onto the arcuate contactors a and b just before it passes 01! the contacts 0 and d, the buzzer circuit will be established and this buzzing will be continued during the time when the lever arm 85 is about to break the circuit across 0 and d and also during the entire time the bar 89 is in contact with and closes the circuit across the arcuate contacts a and b.

The solenoid I28 can only be operated when the circuit across the contacts a, his closed. When the switch 85 is thrown to the dot-and-dash position of contacts 88 and 89 (see Fig. 7) by placing the rod 5| in the slot portion 51, both the motor circuit and the solenoid circuit will be opened.

To disconnect the buzzer, if desired, the switch 92 may be actuated, while to disconnect the entire safety device, the switches 13 may be thrown to contacts 0, 1).

It is thus apparent when the film becomes loose at the position 24 due to any stoppages or disruptions, the rod '22 will immediately move in such direction as to move the pivotal arm 85 in the direction I88, as indicated in Fig. 7. This will cause deenergization of the relay solenoid 91 and operation of the solenoid I28 to cut off the aperture 8, thus assuring that the film will not catch on fire due to being heated to ignition temperature by the beam of light I I.

The operation of the safety device takes but a few seconds and will take place in a much shorter interval than is required to heat the film up to ignition point.

At the same time the buzzer 94, which becomes active just prior to the time the circuit between the contacts 0 and d is broken, will continue buzzing to indicate to the operator that either the machine is in danger of being thrown off or has been thrown off.

The buzzer 94 may be replaced by a light, if desired, but as a general rule the light IN is best utilized to indicate when the automatic safety device is in operating position.

When the rod 5| has been placed in. the right angular portion 51 of the slot 52, the contact bars 88 and 89 will be ofi both pairs of contacts 18 and 1| as shown by the dotted lines in Fig. 7.

I It will be noted that only four connections need be made into the box A indicated by the double dot and dash lines in Fig; '7. These connections are 88, 18a, 98a and 18 and they may all be included in a single cable.

It is thus apparent that the applicant has provided a simple, inexpensive attachment for moving picture machines which will greatly decrease the hazards due to fire and also will automatically throw out the machine and/0r cut off the beam of light when the film is in danger of being stuck in front of or in the path of the beam of light with possibility of ignition.

The apparatus may be readily attached to motion picture machines now in use without special reconstruction or adjustment and assurance is had that the device will work over long periods of time without difllculty.

Many other changes could be effected in the particular features of safety device for moving picture projectors disclosed, and in specific details thereof, without substantially departing from the invention intended to be defined in the claims, the specific description herein merely serving to illustrate certain elements by which, in one embodiment, the spirit of the invention may be efl'ectuated.

What is claimed is:

1. In combination. a circuit for operating an electro-magnetically operated dowser device, a motor circuit for operating the motor of a motion picture projector, a buzzer circuit for operating a buzzer, a main switch provided with a follower member contacting with the film, said switch being moved by said follower member to one position upon normal operation of the film to a second position upon undue slacking of the film preparatory to a break, and to a third position when the film has broken, a relay having an electro-magnet and a double acting switch controlling said motor circuit, said main switch controlling said electromagnet to cause said relay switch to close said motor circuit when said switch is in first and second positions and to open said motor circuit when said switch is in the third position, said main switch also directly energizing said buzzer circuit when said follower is in the second and third positions, said main switch controlling said relay switch to control said dowser circuit and to close said dowser when said main switch is in said third position, said buzzer being actuated before said dowser.

2. The combination of claim. 1, a light being also provided to indicate when said main switch is operating and a circuit actuated by said switch to illuminate said light, said circuit being closed by said main switch throughout the period of operation and means to move said switch to a position where it will open the buzzer, the relay and light circuits.

3. In combination with a moving picture projector safety control system having projection means to project a light beam feed, a motor to feed film across said projected light bearmprovided with a motor circuit, dowser cut 01! means to cut off said light beam from said film provided with an electro-magnet to control said dowser cut 01! means and with a dowser circuit and a double acting relay switch to control said motor and dowser circuit provided with a relay circuit and a signal provided with a signal circuit; a switch control box having a reciprocating elongated spring biased rod with a roller follower contacting said film, a pivotally mounted contactor arm, a linkage between said rod and arm, two pairs of arcuate parallel conductor bars positioned in said relay and signal circuits, said bars being radially spaced from each other and said pairs slightly overlapping and being at diiferent radial distances from the pivot mount of the arm, offset straight radial bars on said arm riding over said respective pairs and said relay operated by opening or closure of circuits across one of said pairs of contacts by one of said bars to close a circuit to said relay to actuate said relay to energize said motor circuit when the film is normally operating and in another position to close the signal circuit to said buzzer and operate said relay circuit to open said motor circuit and to close said dowser circuit to operate said out of! means.

4. In combination with an electro-magnetically operated dowser device, a relay controlled motor circuit and a signal circuit. for a moving picture projector, a switch operated by breaking or a slack in the film, said switch being normally in oi! position and when in said position operating said relay to close said motor circuit and when in another position upon slacking or breakage of the film operating said relay to open the motor circuit, energizing said signal circuit to operate said signal and operating said electro-magnetically opebrated dowser device to cut the projected light eam.

JOSEPH JACOBSON. NATHAN GRANATSTEIN. 

